observer

observer

This library implements the pub/sub pattern in a generic way. It uses Go's generic types to declare the type of the event.

Differences between v1 and v2

The v2 release contains breaking changes. The most important ones are:

• The Observable interface does not provide a Clients() int64 method anymore.
• The constructor NewObserver() has been removed. Instead, use new(observer.Observer[T]).
• The Observer has become a NotifyTimeout that can be used to set a timeout for the NotifyAll method. The default value is 5 * time.Second.

Usage

go get github.com/leonsteinhaeuser/observer/v2

Example

package main

import (
    "fmt"
    "github.com/leonsteinhaeuser/observer/v2"
)

type Event struct {
    ID      int
    Message string
}

var (
    obsrv *observer.Observer[Event] = new(observer.Observer[Event])
)

func main() {
    rspCh, cancelFunc := obsrv.Subscribe()
    defer cancelFunc()
    go func() {
        for {
            fmt.Printf("Received event: %v\n", <-rspCh)
        }
    }()
    fmt.Println("Registered Clients: ", obsrv.Clients())

    obsrv.NotifyAll(Event{
        ID:      i,
        Message: "Hello World",
    })
}

If you would like to see a more detailed example, please take a look at the observer example.